Secure integrated circuit cards, commonly referred to as smart cards, are available in a variety of shapes and sizes. Smart cards can be used to store and share information. Smart cards can be small enough to fit into a user's pocket or into a variety of electronic devices. Smart cards can be used in various electronic devices, including phones and personal digital assistants. Smart cards can be used for a number of different applications, including electronic payment systems, and for storing personal information. For example, a smart card can be used to store user account information and be included in a set-top box to facilitate pay-per-view or video-on-demand features and assist in the decryption of encrypted digital video streams. The smart card may communicate with a video provider to accomplish these tasks. As another example, a smart card such as a Subscriber Identity Module (SIM) card can be used in a mobile phone to store a user's personal information, such as his or her phone book, device preferences, saved text or voice messages, service provider information, etc. Storage of such information in a SIM card can enable a user to change phones while retaining their individual information (i.e., on the SIM card).
Smart cards may be structured to be compliant to various standards. Examples of standards include the ISO 7816 standard, ETSI standard, and EMV standard. The smart cards may also communicate with external devices using a variety of communication interfaces, such as an ISO 7816 interface, a USB interface, a MMC interface, and/or a SWP interface.
Based on an given application, a smart card may be configured to operate in a particular voltage class. In current conventional applications, each class defines a different voltage level as follows: class A devices operate at a voltage level of 5 volts +/−10%, class B devices operate at a voltage level of 3 volts+/− 10%, and class C devices operate at a voltage level of 1.8 volts+/− 10%. Typically, a smart card is configured to operate in a singular desired voltage class.